"As artists we have an ability to reach a lot of people in a deep way, and we have a responsibility," he said. "What we have to do as storytellers is to take science and make it relatable.

"I think we have to tell the story of the positive and what we're going to try to do. Give them alternatives but don't make it a polemic."

Ruffalo, a long-time environmental activist, added that the current trend of doomsday and end-of-the-world movies is the result of art reflecting real-world discussions and concerns.

"I'm in The Avengers, but if you took my screentime it would come to about ten minutes, along with the 12 other people I'm sharing the screen with, so my input's kind of limited on that. But if we get to a standalone Hulk movie, I'll have a much better chance to do that. I'm just learning now how to find my voice and bring it into the studio world."

Ruffalo, who in 2010 founded the clean water organization Water Defense, recently said in the "Inquisitive Minds" podcast, that the time was now to move away from dirty fossil fuels.

“For the first time in human history, we’re actually at a place, technologically speaking, where we can make this transition,” he said. “And the amount of money, and resources, that we pour into this fossil fuel infrastructure, which has been an appendage to us, like a third leg that we’re dragging around, will be freed up, and no longer will we be worrying about having to extract energy. We’ll be just harvesting what’s already pouring on us every single day.”